Weld heads are commonly used to spot weld two or more metal components, such as two overlapping sheet metal components, together. Weld heads commonly include a pair of opposing electrodes configured to both supply pressure to clamp the components together and supply current through the components. Weld heads may alternatively include a pair of side-by-side electrodes configured to supply current through the components. As current is passed through the electrodes, the electrical resistance supplied by the components tends to locally heat the components around the points of contact of the electrodes or at the mating surface of the components, thereby locally melting the metal components together to form a spot weld.
Additionally, conventional weld heads are configured to support a variety of different configurations of electrodes. Different configurations of electrodes may be selected based upon the desired size of the spot weld and the configuration of the metal components to be welded. However, removing and replacing the electrodes on conventional weld heads may be cumbersome and time-consuming. Additionally, it may be difficult to properly align the electrodes on conventional weld heads because the electrodes must be installed in situ. Moreover, some conventional weld heads are susceptible to temperature variations that may adversely affect the force output of the electrodes and thereby the quality of the resultant spot welds. Furthermore, conventional weld heads incorporate a linear actuator motor to adjust the position of the electrodes. Such conventional weld heads are susceptible to variations in clamping force depending on the position of the linear actuator motor because the strength of the magnets in the linear actuator motor varies along the stroke of the motor. Additionally, when the power supply is cutoff from conventional weld heads, the electrodes tend to strike each other, which may damage or prematurely wear the electrodes.